Method of treating keratinous yarns and compositions therefor



Patented June 16, 1953 METHOD or TREATING 'KER'ATINOUSQ mans ANDCOMPOSITIONS 'rnannroa .Qscar 13; Cohen, Watertown, Mass, assignor. to

Monsanto Chemical Co r A y, u l. Mon castr o P Delawar NoDrawing.Application October 1-, 1948,; SerialNo. 52,427"' w re 325 1 4 ihepresent invention relates. to an improv I process of setting the twistof mechanically twisted keratinous. yarns. and particularly high ytwisted keratinons yarns employed in the manfa tu o pile fabrics, friezeug and th ke- The present invention also. relates to a method omtroducing k ks in hi hly twisted .ke a n u yarns and. simultaneouslytherewith. setti g. .01 kinks.

n e ma u acture of twisted ke atin u yarns such as twisted ,woolyarnswhich are em.- p o ed. in the p oduct o of hi h u lity f ie s, e b sand. the: l ke. i has e n m r to. set t e w st o t r s b h sical andmechanical. methods. However, such methods have not been entirely.satisfactory both m the s n no n o cos an the permanen of the set whichhas been imparted to the twisted. yarn. For example, it is known thatWhile I Pu s and pile fabrics fabricated from the. twist: ed yarns whichhave been set by the. aboveprocesses, are superior to rugs and pile.fabrics fabricated from twisted yarns. which have not. been set,. theyarns therein are not set with suflicient permanence to withstand :a'numberof. aqueous cleaning operations without losing a, con-9 siderableamount of their twist. The result is that the rugs or pile fabrics whichare-cleaned h man er u r o mark han e 1 the appearance ofthe. pilel structure,

The present invention provides a processwhich not only obviates theabore described- ,disadr vantages, but also makes it. possible toset't'he twist of keratinous yarns, which'h'ave been given a high degreeof twistgtol an extent which has not been possible by the prior. {artprocesses. I It is,.,a.ccording 1y, one ObjeIctof'th present inventionto provide a simple. and. .efiicient process for setting the twist ofmechanically twisted keratinous yarns .such as wool yarns whereby thetwisted yarn possesses; after fabrication into a pile fabric, a highdegree-of resistance to untwisting when such fabric-is-subjectedtoaqueous cleaning operations. 7

A. further object of the present: invention is the processing of highlytwisted keratinous, yarns such as wool yarns.- whereby thetwist of theyarns is, set and made-resistant to untwisting when subjected .tohotaqueous: solutions;

A further. object oftheapresent invention is the introduction of'kinksin highly. twisted he: ratinousv yarns and the: simultaneous settingthereof whereby the yarn; retains such kinks when fabricatedrinto rugs;and thencleaned-by aqueougcleaningmethods. V

A further object of the present. invention .is l

the preparation of novel twisted keratinous yarns which. are resistantafter fabrication into pile fabrics to untwisting when such fabrics aresubjected to aqueous cleaning methods or are treated with hot aqueoussolutions.

.Still further objects and advantages. ,of the invention will appearfrom the. following. descrip tion and the appended claims... 1

The present inventionvis carried out in general by first. treatingtwisted keratinous yarns such as twisted wool yarns, twisted mohairyarns and the like at about 1.0 to 150? F. with an aqueous dispersioncomprising a reducing agent capable of splitting the characteristiccystine linkage of keratin, preferably, reducing agent such. as mercaptocompounds having. at least one hydroxyl group and containing from 2 to 6carbon atoms, and a light stable thermoe plastic, resin which when dryis substantially nontacky. V r

As examples of suitable thermoplastic resins may be mentionedcopolyrners of styrene: with ie e or isopre vinyl resins s he ystyrenepolyvinyl. butyraln holyvinyl acetate; p ny ao ates. po vinyl ch or deand e k a d --v n d e es s: uc as no yv nylid ne chloride, polyvinylmethacrylatesand the like or o n l me o n l comp unds o v e e om ound .oin l and .v y d ne unds- .A e thea ee a in us arns h ve be re ed a es ied for a e iod o t e i n t ceuseea onof abou to by wei t .Of re u i a ntw t t ke a n ba ed n t eo sh aoi t k ra .ou a n the a I x r ted t remo eces 'liquidt e efr'om nd thendri d a t mne atu e b e n about -.35 .F1-heram mar hetu ther nshed i des ed by Washin h m w th an a ua so uti nomsris ne a emul i i age nd n .oiei iz ne. a ent] ca able o re d g withthe r s dua un ee ted: redu n agent in the w est edh ndryin l Th venti nat. h prac ise on d ed P undyed at ous yarn H wever if the ais edra n arto .be empl yed in .a loreo r o nileabr a; t e shon d b d ed n i r treatme i b cau e-- th fin sh mpar ed to t e ra n e nts-seti a to r.dyenel ne twis a ifi k i he finis ed arn s set quite permanent y y.e'process. de r bed h e:

in;-v When 'suchyarn is fabricated into a pile fabric, it is resistant".to untwisting' ,when. the fab.- ric isnsubjectedto rug: shampooing andother aqueous cleaning operations or whensthe .pile

. 3 fabric is wet out with hot aqueous solutions. In addition, thetensile strength and abrasion resistance of the yarns is not appreciablyaffected by such processing.

In carrying out the present invention, best results have been obtainedby employing mercapto compoimds having one or more hydroxyl groups andcontaining from 2 to 6 carbon atoms, since such compounds react with thekeratin molecule more readily than other reducing compounds. Thesecompounds are also used advantageously since they are compatible withmost vinyl or vinylidene aqueous resin dispersions at the tem= peraturesemployed herein, that is such compounds do not ordinarily causeprecipitation of the dispersed vinyl or vinylidene resin particles.-

Moreover, it has been found thatsuch mercaptans do not adversely affectthe light stability of vinyl or vinylidene resins. However, it ispossible in some instances to employ other organic and inorganicreducing agents which are capable of splitting the cystine linkages ofkeratin. As examples of such reducing agents may be mentioned inorganicagents such as alkali metal bisulfites, sulfites, sulfides,hydrosulfides and cyanides and the like and organic reducing agents suchas the lower aliphatic mercaptans, water soluble derivatives of sulfinicacids and lower mercapto aliphatic carboxylic acids and water solublesalts thereof such as thioglycollic acid, sodium thioglycollate,ammonium thioglycollate and the like. It ispreferable, particularly whenemploying organic reducing agents of the type described to selectcompounds which have a solubility of at least 1 by weight in water sincesuch compounds are employed in an aqueous dispersion and they do notreact with the keratin to the extent desired if they are notsufficiently water soluble.

As examples of the preferred reducing agents employed in the presentinvention may be mentioned 2'-mercapto ethanol, l-mercapto sorbitol andl-mercapto glycerol.

The organic or inorganic reducing agents employed herein are mosteffective when supplied in an amount sufiicient to react with the woolor other keratin filler to the extent of about 1% to 6% by weight, basedon the weight of the dry keratin yarn. This is readily accomplished whenemploying mercapto-alcohol compounds by treating about 1 part of thewool or keratin fiber with about 20 to 30 parts of an aqueousthermoplast dispersion containing about 1 to 4% by weight ofmercapto-alcohol compound. The treatment is generally carried out atabout 150 F. for 3 minutes or about 100 F. for 60 minutes or betweensuch temperatures for proportionate periods of time depending on thetemperature used. However, the same results may be accomplished atsomewhat higher temperatures or for longer periods of time, and it isonly necessary that the proper weight of mercapto alcohol or otherreducing agent be reacted with the wool or keratin fiber and that thetreatment be carried out at a temperature of at least 100 F.

' A suitable test for determining the amount of reducing agent reactedwith the wool or keratin yarn is to titrate aliquot portions of theaqueous treating solution with iodine, using starch as an indicator, andthen calculate the actual quantity of reducing agent removed from theentire treating solution by reaction with the wool or keratin. Thisvalue is then converted to a per cent value based on the weight of drywool or keratin fiber being treated.

In practicing the present invention, either primary or secondary aqueousdispersions of thermoplastic resin are employed. The term primaryaqueous resin dispersion as employed herein is intended to cover resindispersions which have been prepared by the emulsion polymerization ofpolymerizable monomeric compounds or mixtures of polymerizable, orcopolymerizable monomeric compounds. Secondary aqueous resindispersions, on the other hand, is a term employed herein to designateresin dispersions which have been prepared by dispersing eitherpartially or completely polymerized solid or liquid resin particles inan aqueous solution. This may be accomplished by the use of homogenizingapparatus such as colloid mills and the like or by dissolving ordispersing the resin particles in an organic solvent or plasticizer forthe resin, forming a water-in-oil type of emulsion or dispersion andthen inverting said emulsion dispersion so as to form an oil-in-wateremulsion or dispersion.

The above described resin dispersions may comprise a small amount ofplasticizer for the resin depending upon the characteristics of theparticular resin being used. When the resin used drys to a flexible filmno plasticizer need be employed therewith since the treated wool orkeratin yarn comprising such resin will be sufficiently soft andflexible for its intended use. However, when resins such as polystyrene,polyvinyl acrylates and the like are employed in accordance with thepresent invention, it is desirable to employ a small amount ofplasticizer therewith since the treated wool will have a softer feel andmore flexibility in such instances.

Best results are obtained when from about 1% to 10% by weight of resinsolids, based on the weight of dry wool or keratin yarns, are depositedon the wool or keratin yarn. The twisted yarn may be treated with theaqueous dispersion of reducing agent and resin in a variety of ways. Asuitable method consists in immersing skeins of the twisted wool orkeratin yarns in the dispersion until the desired reaction between thereducing agent and wool is efiected and then centrifuging or otherwiseextracting the treated skeins until the desired amount of resin has beendeposited on the wool yarn. Generally, aqueous dispersions comprisingfrom about 2 to 16% by weight of resin solids are suitable for thetreatment described above depending upon the method of extraction used.

A further understanding of the present invention will be obtained fromthe following examples which are intended to be illustrative, but notlimitative of the scope of the present invention, parts and percentagesbeing by weight unless otherwise specified.

, Example I A primary aqueous polystyrene dispersion was first preparedas follows:

Forty parts of monomeric styrene, 1.8 parts of sodium stearyl benzenesulfonate as emulsifying agent, 0.0? part of NaHzPOr, 0.28 part ofNazHPOi, 0.10 5 part of KzSzOs (catalyst) and 53.55 parts of water wereheated in an inert atmosphere of nitrogen at a temperature between aboutto C. for a period of several hours. The resulting dispersion containedabout 40% polystyrene solids and it was diluted until it contained about4% polystyrene solids.

About 2% of 2-mercapto ethanolwas added to the dilute dispersion ..ofpolystyrene (as preaccess:

pared above) land: the -dispersion-was:heated -to 130 A skein-of highlytwisted-wool car-pet lgsln withzzbutyl ricinoleatev (plasticizc'ar) in ayarn was immersed in the heated dispersionfor about 5 minutes, after:whlch it was centrifuged and thoroughly dried. About parts-ofdispersion were employedsfor 1 partof carpetyarn. The treated yarn waswoven into a pile fabric which was then subjected to several .-aqueouscleaning operations. The twistrand kink-of the treated yarn was notsubstantially :afiected :by such cleaning'operations.

By preparing :an-aqueo'us dispersion contain ing about 25% dibutylphthalat'e "(1313801012819 based on thestyrene monomer in the;preparation of the polystyrene dispersion by emulsion "polymerizationand then treating a highly twisted wool carpet yarn as immediatelydescribedabove,

:it is possible to produce 'a soiter, -a yet noneta'cky yarn.

'E'rample II A .primary aqueous polyvinyl acetate dispersion waspreparedas follows:

Eight hundred parts of water, 10 partsof methyl cellulose v(emulsifyingagent), lO parts of gum arabic (emulsifying agent), 12 a-parts of sodiumsalt of the sulphonic acid-of; dioctyl succinic ester (surface tensiondepressant), 93.0

parts of monomeric vinyl acetate and 1 partof contained about 100%,.based on the weight-of the yarn,of the dispersion andthe yarn was thendried. The treated yarn'was woven into a frieze rug whichwas thengivenseveralaqueous cleanings. 'The kink and twist of the treated yarn wasfound to 'be'set' substantially" fast to such aqueous cleaningoperations.

Earanrmle III One part of highly twisted wool carpet yarn in skeinformwas immersed for-5 minutes 'in parts ofan aqueous dispersiongcontaining5.% polyvinyl butyral (prepared as a secondary aqueous resin dispersion)and 1.5% ,of 2-mercapto ethanol. The dispersion was maintained at atemperature of approximately 150 F.during the immersion period.Thereafter the skein of yarn was centrifuged and dried. The treated yarnwas woven into a frieze rug. The kink and twist of the treated yarn wasfound to be set substantially fast to aqueous rug cleaning operations.

The polyvinyl butyral employed in this example was prepared bycondensing butyralde- Baker-Perkins mill and then slowlyadding watertolthe mix until first awater-rin-oiland then an .oilein-waterdispersion..-is':-formed.

It isapparent, however, thatiother polyvinyl Jbutyrals differinginxhydroxy, acetate :andaeetal composition from the specificpolyvinyl'butyral described above may also Joe-employed. .Moreever, the:aqueous polyvinyl butyral dispersion .mlayabe prepared in. other ways.as. 'for example, zby a homogenizing procedure using a colloid-mi11:.f.0. dispersionpf the r si a i e V V Various.amodifications maybemade in the 1 proc.ess -.d$cribe d herein and -it is intended that theinvention beulimited only by the scope of he-ann n edw aims- Whats-claimed s: H 1. process of setting .the twist of vtwistedkeratinousyarns which consists in treatingsald yarns-with anaqueousdispersion omprising from 2 to 16% by weight o f dispersed particles ofa thermoplastic resinselected ,fromthe group consisting of vinylresins-and vinylidene resins, which resins; aresubstantially non-tackywhen dry.xand from about -1 to 11% of an aliphatic memento alcohol.containing irom 2,1;0 6 carbon atoms which are,-,attached to each otherin a carbo nto-carbon linka e, said compound consisting of.

a; mercapto group, at least one .hydroxyl, group, 163.1bilflfifl0I-I1Sf3l'ld: hydrogen atoms-until from. about 1 to 6% by We ght.based on the weight. .of the, dry ,yarn, of saidmercapto.compound has:

reacted withsaid yarn, .the temperature ofsaid dispersion be ng above=about-100 F. during said. treatment; extractingsaid yarns to. removeexcess-liquid therefrom andto deposit fromaboutl to 10% by weight-oisaid resin particles based on the dry weight.-of;the-yarns;.andthendrying said yarns.

2. A process of setting'the twist .of twisted .leeratinousqyarns whichconsists in treating ,said

.yarnswith anaqueous dispersion comprising from 2.to 16% by weight ofdispersed: polystyrene particles and from about .1 to 14%v by weight ofan aliphatic meroaptoa lcohol containing. from 2 to 6. carbon.atomswhich ,are attached to I each other in =a....carbon-to-carbonlinkage; said compound consisting :of a. mercapto ;group, at least onehydroxyl group.- carbon atoms and hydrogen hyde with a partiallyhydrolyzed polyvinyl acetate and contained on a weight basis 17 to 20%hydroxy groups calculated as polyvinyl alcohol, 7

less than 3% acetate groups calculated as polyvinyl acetate and theremainder substantially atoms, =until from about1= to 6% by Weight,based 011:0 1'l8 W6ifih b. of the dry yarns, of said mercapto compoundhas reacted with said yarns, thetem-- perature of .said dispersion beingbetween about :and.150] F. during said treatment; extracting said yarnsto remove excess liquid therefromandi to -deposit from about 1 to 10% byweightoff said polystyrene particles based on the dry weight. of theyarns; and then drying said yarns.

3. A process of setting the twist of twisted. keratinous yarns, whichconsists in treating said yarns with an aqueous dispersion comprisingfrom about 2 to 16% by weight of dispersed polyvinyl acetate particlesand an aliphatic mercapto alcohol containing from 2 to 6 carbon atomswhich are attached to each other in a carbon-to-carbon linkage, saidcompound consisting of a mercapto group, at least one hydroxyl group,carbon atoms and hydrogen atoms, until from about 1 to 6% by weight ofsaid mercapto compound, based on the weight of the dry yarns, hasreacted with the V yarns, the temperature of said dispersion beingbetween about 100 and F. during said treatment; extracting said'yams toremove excess liquidtherefrom and to deposit from about 1 to 10% byweight of polyvinyl acetate particles.

based on the dry weight of the yarns; and then drying said yarns. 11,.

4. A process of setting the twist of twisted keratinous yarns whichconsists in treating said yarns with an aqueous dispersion comprisingfrom about 2to 16% by weight of dispersed polyvinyl I atoms, until fromabout 1 to-6% by weight of said mercapto compound, based on the Weightof the dry yarns, has reacted with said yarns, the temperature of saiddispersion beingbetween about 100 and 150 F. during said'treatmen't;extracting said yarns to remove excess liquid therefrom and to depositfrom about 1 to byweight of said polyvinyl butyral particles based onthe weight of the dry yarns; and then drying said yarns.

5. A process of setting the twist of twisted keratinous yarns whichconsists in treating said yarns with an aqueous dispersion comprisingfrom about 2 to 16% by weight of dispersed particles of a thermoplasticresin selected from the group consisting of vinyl resins and vinylideneresins, which resins are substantially non-tacky when dry, and

said yarns-to remove excessliquid therefrom and to deposit from aboutlto 10% by weight of said resin particles based on the weight of the dryyarns; and then drying said yarns;

6. A process of setting the twist of twisted keratinous yarns whichconsists in treating said yarns with an aqueous dispersion comprisingfrom about 2 to 16% by weight of dispersed particles of a thermoplasticresin selected from the group consisting of vinyl resins and vinylideneresins, which'resins are substantially non-tacky when dry, and fromabout 1 to 4% by weight of l-mercapto glycerol until from about 1 to 6%by weight of l-mercapto glycerol, based on the weight of the dry yarns,has reacted with said yarns, the temperature of said dispersion beingbetween about 100 and 150 F. during said treatment; extracting saidyarns to remove excess solution therefrom and to deposit from about 1 to10% by weight of said resin particles; and then drying said yarns.

7. A process of setting the twist of twisted keratinous. yarns whichconsists in treating said yarns with an aqueous dispersion comprisingfrom about 2 to 16% by weight of dispersed particles of a thermosettingresin selected from the group consisting of vinyl resins and vinylideneresins,

.which resins are substantially non-tacky when dry, and from about 1 to4% by weight of l-mercapto sorbitol until from about 1 to 6% by weightof said mercapto sorbitol, based on the weight of the dry yarns, hasreactedwith said yarns, the temperature of said dispersion being betweenabout and F. during saidtreatment; extracting said yarns to remove.excess liquid therefrom and to deposit from about 1 to 10% by weight ofsaid resin particles based on the weight of the dry yarns; and thendrying said yarns.

8. A composition for treating keratinous yarns consisting of an aqueousdispersion comprising from about 2 to 16% by weight of dispersed par-Vticles of a thermoplastic resin selected from the group consisting ofvinyl resins and vinylidene resins, which resins are substantiallynon-tacky when dry, and from about 1 to 4% by weight of analiphatic-mercapto alcohol containing from 2 to 6 carbon atoms which areattached to each other in a carbon-to-carbon linkage, saidmercaptoalcohol consisting of amercapto group, at least 1 hydronylgroup, carbon atoms and hydrogen atoms.

9. A composition for treating keratinous yarns consisting of an aqueousdispersion comprising from about 1 to 4% by weight of Z-mercapto ethanoland from about 2 to 16% by weight of dispersed particles of athermosetting resin selected from the'group consisting of vinyl resinsand vinylidene resins, which resins are substantially non-tacky whendry.

OSCAR P. COHEN.

References Cited in the file of this patent 'UNITED STATES PATENTS 7Number Name Date 2,201,929 Speakman May 21, 1940 2,212,744 Masland Aug.27, 1940 2,238,672 Arthur Apr. 15, 1941 2,261,094 Spe'akman Oct. 28,1941 2,403,937 Lubs July 16, 1946 2,499,444 Allison Mar. 7, 19502,509,347 Jackson May 30, 1950 FOREIGN PATENTS Number Country Date17,990/34 Australia June 13, 1934 117,071 Australia June 3, 1943

1. A PROCESS OF SETTING THE TWIST OF TWISTED KERATINOUS YARNS WHICHCONSISTS IN TREATING SAID YARNS WITH AN AQUEOUS DISPERSION COMPRISINGFROM 2 TO 16% BY WEIGHT OF DISPERSED PARTICLES OF A THERMOPLASTIC RESINSELECTED FROM THE GROUP CONSISTING OF VINYL RESINS AND VINYLIDENERESINS, WHICH RESINS ARE SUBSTANTIALLY NON-TACKY WHEN DRY, AND FROMABOUT 1 TO 4% OF AN ALIPHATIC MERCAPTO ALCOHOL CONTAINING FROM 2 TO 6CARBON ATOMS WHICH ARE ATTACHED TO EACH OTHER IN A CARBONTO CARBONLINKAGE, SAID COMPOUND CONSISTING OF A MERCAPTO GROUP, AT LEAST ONEHYDROXYL GROUP, CARBON ATOMS AND HYDROGEN ATOMS, UNTIL FROM ABOUT 1 TO6% BY WEIGHT, BASED ON THE WEIGHT OF THE DRY YARN, OF SAID MERCAPTOCOMPOUND HAS RECTED WITH SAID YARD, THE TEMPERATURE OF SAID DISPERSIONBEING ABOVE ABOUT 100*F. DURING SAID TREATMENT EXTRACTING SAID YARNS TOREMOVE EXCESS LIQUID THEREFROM AND TO DEPOSIT FROM ABOUT 1 TO 10% BYWEIGHT OF SAID RESIN PARTICLES BASED ON THE DRY WEIGHT OF THE YARNS; ANDTHEN DRYING SAID YARNS.